Sparking plug.



N5. 809,578. PATENTED JANA), 1906-.

' W. OTTAWAY.

SPARKING PLUG.

APPLICATION FILED 1133.15. 1904.

"inn, y

umrnn STATES Begum? OFFICE.

W LLIAM .orrAWAY, OF'AURORA, ILLINOIS, ASSIGNOR TO AURORA, AUTOMATIC MACHINERY COMPANY, or AURQRA, ILLINOIS, A

' CORPORATION OF ILLINOIS.-

SPARKING PLUG.

Specification of Letters Patent.

Application filed February 15, 1904. Serial Nv- 193,606.

Patented Jan. 9, 1906.

taon.

1 x This invention relates to improvements in spar-kin plugs for internal-combustion enri gmesj, t e invention relating inore especially to. means for maintaining ti ht joints between the metal body of the ug and the inisulating sleeve, through wl iich passes the stem or electric conductor which leads into zo'the ,e'ylinder of the engine and between the ,said stem or conductor and said insulating- {The invention also includes means for con-' nectin' with said stem the wire which forms fi parto the sparkin circuit.

- My invention l lBTGiH-ShOWITBQS applied to an igniting device ofgthat kind in which the terminals of the conductors between which the sparks are produced are stationary with 3d respect to each other or in which the spark- I 'inlglelectrodes form part'of an open circuit in 'w 'ch current for generating the spark is pro- ;duced by an induction coil ordynamo, and ,y 'said circuit is provided with circuit opening and closing means operated by moving parts of the engine.

The invention may be more readily understood by reference to the accompanying drawings, in which Figure 1 is a view in central longitudinal section with sparking plug embodying my invention. Fig. 2 is a cross-section of the same, taken on line 2 20f Fig, 1. Fig.3 is a Fig. 1'.

As shown in said drawings,. A indicates a part of thewall'of' the ower-cylinder of an explosive-engine, and the tubular metal body portion of the sparking plug which is inserted within a screw-threadedhole in said wall A in the ordinary manner. 0 indicates the insulating sleeve, tube, or plug, which passes through the metal body enters the body cross-section of the same, taken on line 3 3 of B and-forms an insulating-support for the metal rod or stem D, Whic passes centrally through said sleeve or tube and forms a part of the conductor of the sparking circuit. Said rod D is provided at the inner end of the sleeve 0 with a head D, which constitutes one sparking terminal of the igniting device. This head is shown as consisting of an integral enlargement on the stem, which is,sur- V rounded by a coating or covering (1 of German silver, platinum,-or the like. The other sparking terminal is formed by a metal arm E, which is secured in the inner end of the tubular body B and the free end of which is bent toward and terminates near said head D.

Said armE will usually be made of platinum.

At its outer end the stem D is connected with a wire F, which leads to one of the terminals of an induction-coil or other current-generating device.

The insulatin -sleeve O'is secured in the tubular body B y a construction as follows: Said sleeve 0 is with an annular enlargement C, at the. ends of which are formed shoulders c c. The main part or body of the plug 3 is provided with a recess somewhat arger than the enlargementjC. At the inner end of said recess is formed an annular faces toward or comes opposite the shoulder c on the latter. The inner end of the sleeve 0 inside of the shoulder c is made somewhat smaller in diameter than the part of the body A- which surrounds it, so that these parts are. out of actual contact when the sleeve is inserted on the body. A packingring or gasket G, of asbestos, mineral wool,

, or other suitable material, is inserted between the shoulders E) c. The outer end of said tubular body B is screw-threaded toreceive a land H which is made of suitable i11- terior diameter to receive the reduced part of the sleeve C outside of the shoulder 12 Without contact therewith. The inner end of said gland forms a shoulder which comes oppositeand faces toward the said shoulder a. A packing-ring. or gasket G, also of asbestos, mineral wool, or the like, is interposed between said shoulder c and the shoulder h on the inner end of said gland H.

When the sleeve 0 is inserted in the body part B of the plug, together with the packing provided at its part which shoulder b, which when the sleeve is in place I rin s G G, and the gland H is tightened, the sait l sleeve will be firmly held in the body art and tight joints will at the same time be ormed between said sleeve and said body art. The said tubular part B and sleeve 0 being so arranged that they will be free from contact with each other, the sleeve will be supported in the tubular body solely by the packing-rings or gaskets G G. This construction and arrangementof the parts serves to aflord a strong and rigid sup ort of the insulatin sleeve within the tubu ar metal body, Will 6 ,at the same time permitting the said body to freely ex and and contract under the influence of eat and cold without liability of breaking the insulating-sleeve, which is usually made of porcelain or the like. By making the packing-rings orgaskets G G of asbestos or mineral wool, moreover, tight joints, which will be unaffected by heat,- are provided between the insulating-sleeve and tubular body B, by which escape of gases and products of combustion from the interior of the cylinder is prevented.

Now referring to means shown for maintaining a tight joint between the stem D and the insulating-sleeve 0 these parts are made as follows: In the inner end of the sleeve 0, surrounding the central aperture thereof, through which the stem D asses, is a cavity c 0r recess C, in which is p aced' a gasket or other suitab e material.

packing-rin I, of abestos, mineral wool, or The shoulder formed on the stem by the inner end of the head D and the bottom of the cavity or recess C form op osed surfaces or shoulders between which t e packing-ring I is held or com pressed under endwise tension on the rod. In other words, the longitudinal passa e in the sleeve has an inwardly-facing shou der and the stem an outwardly-facing shoulder, between which the packing is adapted to be clamped or compressed by outward tension on the stem. At the opposite 'or outer end of said insulating-sleeve C the same is provided with a metal ca J, the same having a tubular part which its over and adapted to slide upon the end portion of said sleeve and a head which is apertured for the passage of the stem D. Between said cap J and the endof the sleeve is placed a packing-rin K, of asbestos, mineral vs 001, or the like, tlie end of the sleeve being preferably provided with an annular groove or rabbet C adapted to receive and hold in place said packing-ring. Surrounding and sliding upon the cap J is a second cap L, the end wall or head of which, like that of the cap J, is provided with a central aperture for the passage of the stem D. Said stem D is screw-threaded on its outer end and is provided with a nut M, which is adapted to bear against the head of the outer or s 1 outward movement on the stem. Between the caps K and L is located a spirally-coiled ding cap L, so as to hold the same from spring N. Said spring'N egcerts a constant pressure on the outer or sliding cap L, tending to hold the same in contact with the nut M and through its pressure on said nut to exert endwise tension on the stem- D, by which the head I) on the inner end of said stem is pressed or held closely in contact with the packing-ring I, thereby maintaining a tight oint between the said head D or the part of the stem adjacent thereto and the inner end ofthe insulating-sleeve. The tension of said spring N also tendsto press or force the inner cap J toward the outer end of the insulatin -sleeve and by compressing the packingring to maintain a tight joint between said cap and the outer end of said insulatingsleeve, The interposition of the said packing-ring K at this point aids in forming a gastight joint between the stem and sleeve and also serves to give cushioned pressure on the outer end of the insulating-sleeve and to thereby prevent -j arring or rattling of the parts under the shocks or jars to which the igniting device is subjected in the operation of an enine. g Devices are provided for connecting the wire F with the stem D, as follows: On said rod D outside of the nut M are placed two telescoping cups 0 and P, the end walls of which are apertured for the insertion of said rod D and which are adapted to move or slide freely on the rod. Inside of said cups 0 and P, between the end walls thereof, is loeated an expansively-acting spiral or coiled spring Q, the tension of which tends to sepa rate or spread apart said cups. Upon the said rod D, outside of the outermost cup P, is

placed a retaining-nut It. The end of the wire F is coiled about the rod D between'the nut M and the inner end wall of the cup 0, and when the nut It is placed upon the rod and tightened against the outer cup P the inner cup 0, when the spring Q is placed under compression by the screwing up of said nut 11, is pressed or forced toward the nut M, thus clamping or holding the end of the wire F by springpressure. Said spring Q is made of relatively stifi' wire, so that when the nut R is tightened the cup 0 will act with considerable force or pressure against the end of the wire F. By this construction a good electrical connection between the wire and stem will be maintained, notwithstanding the jarring or vibration to which the parts may be subed to act in opposition to the nut M to form forated for the passage of the said stein, a nut with the latter clamping members between on the stem adapted to bear against said sec- I 5 which the end of the wire F is firmly held by end cap, and a spring interposed between the action of said spring Q. said caps and acting to exert endwise tension I claim as my invention on said stem. v w

A sparking plug comprising an insulatingi In testimony that I claim the foregoing as sleeve, a stem which passes through the 5 my inventionlaflix mysignature,in presence 20 sleeve and is provided with a head at its inof two witnesses, this 8th day of February, ner end, a packing interposed between said A. D. 1904.

head and an opposing surface or shoulder on WILLIAM OTTAWAYf said sleeve, a cap applied to the outer end of I Witnesses: said sleeve, a second cap which slides on the Y W. H PEAsE, first-named cap and the head of which is per- I J. SGHUSTER. 

